Ohm

OhmObject hash map Christopher Spring

A littlebackgroundinfo first...

Ohm runs on redis

Ohm runs on redisRemote dictionary server

Ohm runs on redisRemote dictionary serverStore multiple data-structure types

Ohm runs on redisRemote dictionary serverStore multiple data-structure types Lists, Sets, Sorted Sets, Strings, Hashes

Ohm runs on redisRemote dictionary serverStore multiple data-structure types Lists, Sets, Sorted Sets, Strings, HashesIn memory datastore with persistence strategies

Ohm runs on redisRemote dictionary serverStore multiple data-structure types Lists, Sets, Sorted Sets, Strings, HashesIn memory datastore with persistence strategiesSuper fast & easy to scale

Ohm runs on redisRemote dictionary serverStore multiple data-structure types Lists, Sets, Sorted Sets, Strings, HashesIn memory datastore with persistence strategiesSuper fast & easy to scaleAtomic operations & transactions

Ohm runs on redisRemote dictionary serverStore multiple data-structure types Lists, Sets, Sorted Sets, Strings, HashesIn memory datastore with persistence strategiesSuper fast & easy to scaleAtomic operations & transactionsKey expiry

Ohm runs on redisRemote dictionary serverStore multiple data-structure types Lists, Sets, Sorted Sets, Strings, HashesIn memory datastore with persistence strategiesSuper fast & easy to scaleAtomic operations & transactionsKey expiryredis-rb

What is Ohm?

Ancient syllable

Ancient syllableAaa-ooo-mmm

Ancient syllableAaa-ooo-mmmThe beginning, duration anddissolution of the universe

Ancient syllableAaa-ooo-mmmThe beginning, duration anddissolution of the universeBrahma, Vishnu & Shiva

symbol = { :name => Ohm, :description => Ancient syllable, :phonemes => [ { :sound => aaa, :meaning => beginning of the universe, :god => Brahma }, { :sound => ooo, :meaning => duration of the universe, :god => Vishnu }, { :sound => mmm, :meaning => dissolution of the universe, :god => Shiva } ]}

Let’s store that inredis...

require redisdb = Redis.new

# make a bunch of phonemes# HMSET key field value [field value ...]phos = %w(pho1 pho2 pho3)db.hmset phos[1], sound, aaa, meaning, beginning, god, Brahmadb.hmset phos[2], sound, ooo, meaning, duration, god, Vishnudb.hmset phos[3], sound, mmm, meaning, dissolution, god, Shiva

# ... and create the symboldb.hmset symbol, name, Ohm description, Ancient syllable, phonemes, phos.to_json

require redisdb = Redis.newphos = %w(pho1 pho2 pho3)db.hmset phos[1], sound, aaa, meaning, beginning,god, Brahmadb.hmset phos[2], sound, ooo, meaning, duration,god, Vishnudb.hmset phos[3], sound, mmm, meaning, dissolution,god, Shivadb.hmset symbol, name, Ohm description, Ancient syllable, alternatives, alternatives, phenomes, phos.to_json

Awesome?

I want lot’s of Symbols

I want lot’s of Symbols db.hmset symbol, name, Ohm description, Ancient syllable, alternatives, alternatives, phenomes, phos.to_json

I want lot’s of Symbols

I want lot’s of Symbols Require a key strategy

I want lot’s of Symbols Require a key strategy Store the key in redis

I want lot’s of Symbols Require a key strategy Store the key in redis Auto-increment

# "symbol:1", "symbol:2" ... "symbol:n"def get_symbol_pk pk = db.incr symbol:pk "symbol:#{pk}"end# ...db.hmset get_symbol_pk, ...

Ok, but...

I wanna find symbols byname!

I wanna find symbols byname!Requires an extra index

I wanna find symbols byname!Requires an extra indexStore index in a hash or a set

I wanna find symbols byname!Requires an extra indexStore index in a hash or a setWe need an index key strategy

I wanna find symbols byname!Requires an extra indexStore index in a hash or a setWe need an index key strategy...

SYMBOL_NAME_INDEX = symbol:index:namedef store_name_index symbol_key, name db.sadd "#{SYMBOL_NAME_INDEX}:#{name}", symbol_keyenddef find_symbol_by_name name db.get "#{SYMBOL_NAME_INDEX}:#{name}"end# Transaction...db.multi do symbol_key = get_symbol_pk db.hmset get_symbol_pk, name, symbol_name, ... store_name_index symbol_key, symbol_nameend

Fine, but now i want...

Fine, but now i want... Validation

Fine, but now i want... Validation To use this in project X

Fine, but now i want... Validation To use this in project X To be able to find the symbol of a phoneme

Fine, but now i want... Validation To use this in project X To be able to find the symbol of a phoneme ... shoot me?

This sucks!! Not OO at all Validation? Referencing containing object What other pitfalls have we missed? Project/implementation specific ...

Let’s build our own objectmapping on top of redis!

Ohm: Object hash map

symbol = { :name => Ohm, :description => Ancient syllable, :phonemes => [ { :sound => aaa, :meaning => beginning of the universe, :god => Brahma }, { :sound => ooo, :meaning => duration of the universe, :god => Vishnu }, { :sound => mmm, :meaning => dissolution of the universe, :god => Shiva } ]}

require rubygemsrequire ohmclass AncientSymbol < Ohm::Model attribute :name attribute :description index :name collection :phonemes, Phoneme def validate assert_present :name endend

class Phoneme < Ohm::Model attribute :sound attribute :meaning attribute :god index :sound index :god reference :ancient_symbol, AncientSymbol def validate assert_present :sound endend

Ohm.connectsymbol = AncientSymbol.createp symbol.valid? # falsep symbol.errors # [[:name, :not_present]]

error_messages = symbol.errors.present do |e| e.on [:name, :not_present] do "Symbols must have a name." endend

symbol = AncientSymbol.new :name => Ohmif symbol.save symbol.phonemes << Phoneme.create( :sound => aaa, :meaning => beginnging of universe, :god => Brahma, :ancient_symbol => symbol ) # ...end

Cool, so how do find stuff?

Phoneme.all

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]# <Phoneme:1 ancient_symbol_id="1" sound="aaa"

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]# <Phoneme:1 ancient_symbol_id="1" sound="aaa"meaning="beginnging of universe" god="Brahma">

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]# <Phoneme:1 ancient_symbol_id="1" sound="aaa"meaning="beginnging of universe" god="Brahma">pho.ancient_symbol

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]# <Phoneme:1 ancient_symbol_id="1" sound="aaa"meaning="beginnging of universe" god="Brahma">pho.ancient_symbol# <AncientSymbol:1 name="Ohm" description=nil>

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]# <Phoneme:1 ancient_symbol_id="1" sound="aaa"meaning="beginnging of universe" god="Brahma">pho.ancient_symbol# <AncientSymbol:1 name="Ohm" description=nil>symbol.phonemes

Phoneme.all# <Set (Phoneme): ["3", "1", "2"]>Phoneme.all.except :sound => ooo# <Set (Phoneme): ["3", "1"]>Phoneme.find :sound => aaa# <Set (Phoneme): ["1"]>pho = Phoneme[1]# <Phoneme:1 ancient_symbol_id="1" sound="aaa"meaning="beginnging of universe" god="Brahma">pho.ancient_symbol# <AncientSymbol:1 name="Ohm" description=nil>symbol.phonemes# <Set (Phoneme): ["3", "1", "2"]>

We also get sorting...

symbol.phonemes.sort# [<Phoneme:1>, <Phoneme:2>, <Phoneme:3>]

symbol.phonemes.sort# [<Phoneme:1>, <Phoneme:2>, <Phoneme:3>]symbol.phonemes.sort_by( :sound, :order => ALPHA DESC )# [<Phoneme:2>, <Phoneme:3>, <Phoneme:1>]

symbol.phonemes.sort# [<Phoneme:1>, <Phoneme:2>, <Phoneme:3>]symbol.phonemes.sort_by( :sound, :order => ALPHA DESC )# [<Phoneme:2>, <Phoneme:3>, <Phoneme:1>]symbol.phonemes.sort_by( :sound, :get => :god )# ["Shiva", "Brahma", "Vishnu"]

What else can we do?

Attribute types attribute set list counter reference collection

Available validation assert_present assert_format assert_numeric assert_unique

ohm-contribBoundariesCallbacksTimestampingToHashWebValidationsNumberValidationsExtraValidationsTypecastLocking

Awesome?

Questions?

Linkswww.christopherspring.comhttp://ohm.keyvalue.org/http://www.redis.io/

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Ohm

by Christopher Spring on Mar 02, 2011

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Ohm — Presentation Transcript